It's all speculation, but I've skated with Tom 3 times(forever grateful). But when I skated with him it was just a tad of booze and or weed, not alot.
I'm not saying he didn't get into other shit cause I honestly don't know, but I'd say an injury/age plays the part the most.
I've said it on here numerous times, as dumb as this sounds, in his prime he was WAAAAY fucking better than what was documented. Penny did hardflips like Herman 20 years ago.
Travis stenger was alot like penny(although not nearly as good) he would just sit for an hour or two, get up and withing 5 minutes you were witnessing pure magic on a skateboard.
Not to bring stenger into it, but I knew him. Pretty sure they both have some mental issues, like possibly social anxiety? Both were really self conscious and seemed to use drugs/alcohol to separate the mind from the crowd. Mike Carroll is the same too. Like they know the spotlight is on them and it's too much. But all accounts of penny seems like he had zero clue the spotlight was on him, that's complete bullshit.