Some may recall that Central Trains abolished reservations after finding they could not reliably implement them. If that's true of TPE, they should go the same way. There's little point having them if they are not reliable.
It's true that there's little point in having them if they're not reliable, but then there should be substantial pressure from the regulatory authorities on TPE to make them reliable. Not being able to reserve between, say, Leeds and Manchester, or Manchester and Liverpool is not too bad, even on trains routinely too well filled for comfort, but not being able to reverse between Manchester and Glasgow or Leeds and Newcastle on those same trains is just not acceptable on a modern railway.