Ignoring patents ignores the purpose of the patent system

From the brief of Mark Lemley in GLOBAL-TECH APPLIANCES INC:

In the fast-paced industries of the current economy,
the quantity of patents, the almost glacial process of
patent prosecution, and the uncertainties surrounding
patent scope and validity frequently make it impractical
to conduct a patent search before launching a product.
In fact, it has become common practice in many of our
most innovative industries to put a product on the
market before doing a patent search and to then “wait
and see” if a patentee claims infringement. See Mark A.
Lemley, Ignoring Patents, 2008 MICH. ST. L. REV. 19, 22
(2008). In response to a 2003 survey, fifty-three percent
of intellectual property managers disagreed with the
statement “[w]e always do a patent search before
initiating any R&D or product development effort.” Id.
at 22 (citing Iain M. Cockburn & Rebecca Henderson,
Survey Results from the 2003 Intellectual Property
Owners Association Survey on Strategic Management
of Intellectual Property F.6 (Oct. 2003)). And the
Berkeley Innovation Survey of start-up companies found
that in the information technology industries less than
a quarter of companies regularly searched for patents.
Stuart J.H. Graham et al., High Technology
Entrepreneurs and the Patent System: Results of the
2008 Berkeley Patent Survey, 25 BERKELEY TECH. L.J.
1255, 1321–22 (2010).

See also
Patent Case Draws Concern