Let's analyze this recent post.
He has ONE and it's not that good, can pretty much only be used to remove the opponen't option to jump in some situations and hit them as they are falling/bait an airdodge in others.
-horizontal recovery and 2 vertical recoveries
Luigi may have good recovery options but they are predicatable as hell. If you have trouble edgeguarding Luigi, it is either to lack of experience in doing so or from using a character unsuited to such a task. (Ex: Ivysaur)
-you can still jab cancel into upB
This is a frequent misconception, both in vB and B+. Luigi's Jab Cancel > UpB only truly works on a select few characters (such as ROB, for example). Just inputting shield at rougly the right time will usually buffer into a powershield unless the opponent is airborne when jabbed(and thus unable to shield). There is a thread including a very detailed chart (with frame data) in the Luigi subforum I could find and link, if you absolutely need proof.
-crawl to avoid some projectile spams, not all
Luigi does have a good crawl and crawldash, I'll give you that. I'm not just trying to negate every point you brought to the discussion.
Luigi has amazing killing power, the moves are just hard to combo into or set up due to lack of range. Shoryuken, up-angled forward smash, the occasionnal bull****-random-Misfire and Nair for later percents are all very good killing moves, but they are hard to use. Luigi mains have to work hard to get an early kill. ask any of them.
Spamming one move doesn't work against any half-decent player. You should know that. Bair is fast, has good priority and is Luigi's aerial with the most lateral range, but any move with a disjointed hitbox will eat through it or clank. Opponents can just shield it and grab if you spaced it wrong or just retreat/attak if it was spaced correctly.
Try bairing trough a noob Marth spamming fair and you'll see how useless bair can be in some situations.
The Dair spike hitbox was improved 1.5x in size in B+ and the knockback was increased as well, it also comboes into a footstool fairly often when landed. I won't hide that it's good.
But keep in mind that even though Luigi has a spike, it's very hard to use. You basically have to hit oyur opponent with ONLY Luigi's butt-area, while avoiding hiting with any other hitbox (basically the rest of his feet, legs and waist). Any opponent with a disjointed UpB will hit you through it if they time their UpB right, as well.
-downB tech chases really well
Again. You are right. Luigi cyclone is crazy-fast, has good priority - Hell, it even clanks with most get-up attacks if you miss your techchase. But other than that, you usually have better techchase options. You can't really combo off of DownB anymore except at low percents and it doesn't do that much damage.
It is a very good techchase move, but unless you're high in damage and you don't want to take the risk of getting punished, or you've played your opponent enough to start reading their habits, there are nearly always better options.
I exaggerated. He's not broken, but insanely hard and annoying to deal with.[
Luigi is not broken. he is, as you say, very hard to deal with if you're using characters that fail at exploiting his weaknesses stated above. Luigi is good against many characters in the roster. At same level,however, Marth, Meta-Knight, and similar characters utterly destroy Luigi.
Edit: I'm thinking about making a new Luigi B+ thread to start from scrath and actually have matchups, discussion and stuff, instead of the huge abandoned pile of fail this thread is.
Thoughts?