We all take them for granted, those black rubber hoops that provide all important contact between bike and road but in order for them to do their job they need to be working properly. There are a number of different conditions that you could find your tyres in that will make a difference - so lets go throguh them!
First and foremost lets get tyre pressure out of the way, each tyre and bike has an optimal setting in either BAR or PSI, a smidge under that and may will find that the bike feels as if it is moving underneath you, a gnats hair over and you get the opposite effect where the tyre simply does not seem to be moving enough. Feeling aside there are a couple of important things happening that you should know about, when your tyre is at its optimal pressure the contact patch between the tyre and road is at its optimal so you have the right amount of rubber between you and the right feeling when you need to change direction, by reducing this pressure by a couple of psi you are allowing the structure of the tyre to compress slightly which is resulting in a more spread out contact patch but is not staying in the shape you want for direction changes - this can result in a sluggish and unresponsive feel to the bike.
The same but opposite effect is in play when the tyre is over pumped, the sidewalls and carcass is not given the opportunity to flex and move when required and as a result your contact patch is greatly reduced when you need it most - and seriously - when do any of you need less grip on the road? When checking your pressures it is important to use an accurate gauge, a lot of people recommend a footpump over a filling station for this reason as those air pumps are used a lot and calibrated very little.
Secondly you have seen that the middle section of your tyre is squaring off, this is not so much an issue but a sign of the kind of mileage you do on the bike with loads of straight boring roads and very little opportunity to get the bike cranked on its ear. Squaring off does affect the bikes handling with a little resistance on first banking over then dropping in quite well when it reaches the rounded edge, this gets worse the more squared the tyre but the important thing here is to be aware of the difference in feeling and ride with that in mind.
Finally, if you are a fast road rider or trackday enthusiast you will no doubt have noticed bobbling and a blue hue to the very edges where you have had the bike on its side and worn away any reference to a chicken strip. What you are seeing is not the grippy part of the tyre wearing out but simply an indication of the temperature going through it - with bobbling it is enough there to start forcing the small shards of rubber (well actually no rubber is found in modern tyres) that are heated up into tiny balls.
Most of all though you should keep an eye over your tyres before riding your motorcycle, these are the only contact you have with the tarmac and knowing the condition they are in for each ride may just help keep you safe.