I agree with that, but it has to be so good & have such a wow factor that people will be willing to change platforms, see it's not just about the phone anymore it's also the ecosystems. Unfortunately unless there is some crazy security breech or Google gets exposed for doing some crazy **** you won't ever see an Android user who is entrenched in the Google ecosystem & uses Google services to change to a ecosystem that does not have Google services and apps, Google knows this that's why they do not & will not have apps for WP. They know as soon as they do they will loose customers because it will be a lot easier to switch.
Right now is like the early 90's of the desktop computer era where Apple is still apple, Android is Windows & WP is OS/2 or Linux. It didn't workout to good for OS/2 and Linux is very niche product although very good no application were written for it & it became a vicious cycle of no apps because no market share & no market share because of no apps. After a few years the other OS's became entrenched & consumers already spent hundreds or thousands of dollars on applications and it did not matter if more apps were available as it was too late. You can see this every time there is a commercial on TV that shows an app available for Android or IOS & not for WP. Every time a smartphone user see's that it reinforces the mind-share for IOS & Android & looses it for WP.
As much as I hate to admit it, W10 is the last chance for Windows Phone to gain mind share & then market share, but MS has to spend a whole lot of cash plus have a "killer" halo phone & very good mid range & low end phones available on all carriers at the same time to pull it off. Other wise plan "B" would be switch to Android as an OS & release a Phone with a windows phone skin with all MS services pre-installed as the default(don't even know if that is possible, I know Google services have to be on the phone also) Cortana, Bing, Live Tiles, etc... Either case they need to get people entrenched in their ecosystem to gain mind & market share.
They also need to bundle phones with tablet & laptop purchases like I see Samsung doing now for W10 launch. Buy a windows phone & get a W10 tablet free or buy a tablet or laptop & get a 535 or 640 free, the only problem is the phone & tablet needs to be available on all carriers for it to work effectively. This would be killer for their enterprise customers. For example buy 500 computers or licenses of W10 and get 500, 640 or 640 XL free for your employee phones.
In any case like I said before they "WILL" have to spend a lot of money & I mean "A LOT" for a sustained "Shock & Awe" ad campaign for several months if not a full year & paying carriers to not have exclusive phones & have the same phone on all carriers at the same time.