Massachusetts claim to Maine in the first place was opportunistic and tenuous to begin with whereas the borders of WV and MD (or many of the other states people want to rearrange) have been where they are now for 100+yr.
I strongly believe we only really think that in retrospect because the borders changed long before any of us were born.
Additionally, while splitting off Maine was for a good cause - it was essentially just a hack to keep the senate balanced in the lead-up to the civil war.
Maine brook off because during the War of 1812 England conquered a huge chunk of Maine and the good people of the rest of Massachusetts were too cheap to do anything about it.