You know, I kind of agree and definitely see what you are saying. BUT-- If someone reports a tip and there is no follow-up, it could be that LE got their wires crossed, were pursuing something else and didn't get the surveillance tapes in a timely manner or even get around to interviewing the tipster.
This has come up in other high profile cases where LE opens a tip line. The tip line often receives so many tips that LE doesn't have the manpower to interview each tipster individually.
As I recall from the Horman case, LE looks at each tip and categorises it according to how valuable it may be and whether there is any action that can actually be taken.
A possible sighting of JP 16 miles from home at 6 am would not, in and of itself, be particularly useful. The most useful action would probably be to add a pin to the map of possible sightings (or a dot to the computer display) and see if it contributes as part of a pattern. Being so close to his home, he could have come in from any direction to mooch a free breakfast.
No need to spend the time and money to interview the witness directly.
An example of a tip where there is no useful action that can be taken is a tip from someone who has a psychic vision that the missing victim is in the water (as in the Horman case). Well, that may be correct but the area was covered with bodies of water. Without more specific information than that, there's really nothing LE can do with that information. Again, no need to spend time and money interviewing the tipster.
Even though it would be satisfying to say that money is no object in the investigation of a crime, here in this world it is always a factor. There is always a limit to the amount of money that can be invested in any single investigation.
ETA: I did once call in to a tip line (no, not a psychic vision, either); the operator on the tip line told me that LE might not contact me. And LE didn't, I just took it on faith that either my information was not important or they didn't need to talk to me directly.