I do think it's a valid variant, especially in funners and FFA games. But apart from the WA community's general distaste for change, there are a few problems with playing league Roper on destructible maps that probably contribute to it rarely happening in practice.
For one thing, the map getting simpler and simpler as the game progresses can result in a pretty anticlimactic finish to the longer, more even matches between skilled ropers. Once things get to the point where each player can easily pick up a crate and attack every turn, there's very little hope of coming back for the one who got to the endgame with less health for whatever reason (sometimes through no fault of their own, simply because they didn't get first turn). The way W2 players tackled this problem was to start playing on progressively more complex (and especially higher) maps, which somewhat delayed the point at which the map got to that stage as well as resulted in more opportunity for mistakes that ended games early. But I'm not sure we'd really want to go back to that, from what I remember of those Zillian maps, there was a huge discrepancy between easy and hard crates on them, making it feel like the luck factor of where they landed played a big role in determining the winner. Another related thing to note here is that the W2 Roper scheme punished falling and rewarded good drops that resulted in fall damage rather EXTREMELY, which tended to keep the games shorter and so again made it less likely for the map to get too simple because it was destructible.
In any case, I wouldn't see too much wrong with making the destructible terrain variant of Roper an accepted alternative to whatever the standard Roper scheme currently is in community leagues. The skill set required for playing either variant would in large part be exactly the same, so splitting the Roper player base into two separate camps seems unlikely; we wouldn't end up with one best destructible Roper player and one best indestructible Roper player or anything horrible like that. If the league in question isn't feeling too experimental, have it so that both players have to agree to the alternative scheme before the game starts. If it is feeling experimental, just leave it to the player whose pick it is to decide.
That's my €0.02.