Roach - The Close Season Paradox

‪@MarkWintleFishing‬ With the river close season still in force I'm aware of a disparity in how river and stillwater roach behave. On a stillwater I've been fishing regularly the roach spawned around the 8th to 10th of May and barely paused in their feeding - actually hungrier than ever - yet experience tells me that when the river season reopens on 16th June the roach will be hard to tempt for a few weeks. Whether this is due to a change of diet in summer or other factors I don't know.
One factor on the river close season nowadays is that much of our rivers are unfished these days and abolishing the close season would have zero effect on those waters. Those stretches that are heavily fished, especially those bits that are match-fished, probably benefit from the break, and in my opinion if the close season were to be removed a ban on keepnets, and therefore no match-fishing for a two or three month period would be beneficial. I also think that if river matches were held in the spring the fishing would be very patchy; it's long been the case that early season river matches are often very peggy.